Phonograph



J. T, LEITCH.

PHONOGRAPH.

APPLICATION FILED AUG.I2, I920.

1 89,058. P e A g. 30, 192.1.

2 SHEETSSHEET I.

FIG.1.

UNITED STATES PATENT OFFICE.

JAMES '1. LEITCH, OF ALLENTCW'N, PENNSYLVANIA, ASSIGNOR OF TWO-FIFTHS TO-TILGHMA.N A. FEE-ED, OF ALLENTOWN, PENNSYLVANIA.

rnonoemn.

Specification of Letters Patent.

Patented Aug. 30, 1921.

Application filed August 12, 1920. Serial No. 403,115.

To all whom it may concern:

Be it known that I, JAMES T. Lnrron, a citizen of the United States ofAmerica, residin at Allentown, in the county of Lehigh and tate ofPennsylvania, have invented certain new and useful Improvements inPhonographs, of which the following is a specification.

- This invention relates to phonographs and waves will be obtained andthe absorption and consequent waste of sound producing v1- brations beeliminated.

A third important object of the invention is to provide an improvedarrangement of needle arm and its bracket or support there? for in orderto prevent damping of vibrations by absorption in the body of the soundbox as well as to eliminate the production of metallic. efi'ects.

A fourth important object of the invention is the provision of a novelamplifier so connected with the resonator that the produced vibrationswill be collected and amplified.

With the above and other objects in view, the invention consists ineneral of certain novel details of construction and combinations ofparts hereinafter fully described, illustrated in the accompanyingdrawings, and specifically claimed.

In the accompanying drawings, like characters of reference indicate likeparts in the several views, and

Figure 1 is a front or face view of the improved reproducer.

Fig. 2 is a side view thereof.

Fig. 3 is a back view thereof.

Fig. 4' is an end view taken from the right hand side of Fig. 1.

Fig. 5 is a detail section on the line VV of Fig. 2.

.Fig. 6 is a section on the-line VI-VI of Fig. 2.

Fig. 7 is a detail showing the perforated diaphragm removed from thebox.

Fi 8 is a detail section on the line VII -VIII of Fig.2.

Fig. 9 is a detail section on the line IX-IX of Fig. 8.

Fig. 10 is a face view of a portion of a modification wherein theamplifier is omitted and .the resonator connected to a novel anchorage.t

In the embodiment of the invention herein illustrated there is provideda cylindrical casing 10 having on its front or face end an inturnedflange 11. Within the casing and resting against this flange 11 is anelastic ring 12, which, in common with the other elastic rlngshereinafter mentioned, is preferably made of rubber. Resting beneaththis ring 12 is a ring 13 which has on one side a spaced pair of arms14. terminating in hook shaped portions 15 and forming the fulcrumbrackets as will be hereinafter explained. Below the fulcrum bracketring 13 is a second elastic ring 16 and against the under side of thisring bears the periphery of a sound diaphragm 17.

It is to be noted that this diaphragm 17 is of peculiar character, beingformed from a thin sheet of mica having its surface covered byamultitude of fine particles of metal, the

latter being held on the mica bysome suitable adhesive so that thesurface of the diaphragm appears as though powdered with metal. Theeffect of this metallized mica diaphragm is to render the reproducerresponsive to weak and sensitive sounds while at the same time theovertone waves are properly blended.

Thus the reproduction has all of the characteristics of the originalsound without any harshness or blasting being caused by improper ordefective vibrations in the diaphragm.

Beneath this diaphragm is an elastic ring 18 against the under side ofwhich bears the periphery of a partition (best shown in 'Fig. 7) havingits periphery in the form of a ring 18'. From the peripheral ring 18'lanceolate fingers 19 extend radially inward, being connected to theperipheral ring by narrow necks 20 and termmatmg in points adjacent thecenter of the ring. This partition is made of thin resiliently vibratoryflexible metal and its efiect is to properly blend the tones andovertones, eliminate discordant sounds and assist in increasing thevolume of sound.

Beneath this ring 18 is a resilient ring 21 and held between the ring 21and a similar ring '22 is the periphery of a back piece 23 from thecenter of which projects a tubular nipple 24 whereby the reproducer maybe connected to a phonograph horn or the like. The ring 23 is held inposition by a locking ring 25 screwed into the rear end of the cas ing10. a

From the foregoing it will be seen that the parts 13, 17 and 18 floatresiliently in the casing by reason of their being supported on therubber rings and that the back is also floatingly connected to thecasing.

Considering now the peculiar needle arm arrangement it is seen that thisneedle arm includes a central spindle shaped portion 26 and from theends of this portion 26 project journal ends 27 which are held insleeves 28 carried in the bracket portions 15, these sleeves being ofresilient material, preferably rubber. Projecting in one direction fromthe portion 28 is a tubular needle holder 29 provided with the usualthumbscrew 30 by means of which a needle, such as is shown at 31 in Fig.2, may be held in position. Projecting opposite to the part 29 is a bentfinger 32 the tip of which is attached to the mica diaphragm in anypreferred manner. Thus the vibrations of the needle caused by the recordare transmitted to the dia-- p ragm without passing to the casing as theneedle arm fulcrum, being carried in the rubber sleeves 28, isthoroughly cushioned. Consequently none of the vibrations are absorbedor dlstorted nor are metallic effects produced as is the case whereinthe fulcrum is borne directly on metallic supports carried by or formedon the casing.

Supported on the casing 10 and ring 25 is a bracket 33 carrying anamplifier which includes a casing 34 having a beaded edge wherein arerubber rings 35 against which rests the periphery of a mica amplifierdiaphragm 36. On the other side of this diaphragm is a rubber sleeve 37against which rests a second mica amplifier diaphragm 38, the latterbeing held in position by a retaining ring 39. Thus the amplifier formsa closed box the ends of which are constituted by mica diaphragms.

This amplifier is connected to the other part of the device by anelastic connector constructed as follows: From the center of thediaphragm 36 to the central part of the needle arm extends a gut strand40 which carries, adjacent the amplifier, a spreader 41. From each endof the spreader extends a gut strand 42 which is connected to arespective bracket 14 all of these strands being under slight tensionand firmly secured at their ends to the respective parts. The

elastic connector is thus anchored to the amplifier and to the needlearm and brackets.

In some instances (see Fig. 10) the amplifier is dispensed with and thebracket carries, in lieu thereof, an anchorage 43 to which the strands40 and 42 are attached. In such a case the spreader is omitted as, thestrands all being connected to the anchorage there is no need for such adevice.

This construction gives a heavy leverage in transmitting the vibrationsof the needle arm 29 through the strand 40 whenever the needle moves topull upon said strand and consequently transmits such vibrations to thediaphragm 36. Furthermore, the lateral strands 42 limit the movement ofthe diaphragm 36 whenever the needle arm moves to relax tension on thestrand 40 excessively.

There has thus been provided a highly efficient device of the kinddescribed and for the purpose specified.

It is obvious that many minor chan es may be made in the form andconstruction of the invention without departing from the principlesthereof. It is not, therefore, desired to confine the invention to theexact form herein shown and described, but' it is wished to include allsuch as properly come within the scope claimed.

Having thus described the invention, what is claimed as new, is

1. In a device of the kind described, a sound box having a dia hragm,needle arm brackets at one side of the dia hragm, a needle arm connectedto the diapl iragm and having a fulcrum arranged transversely thereofand supported in the brackets, a second sound box diametrically oppositethe needle arm brackets and likewise provided with a diaphragm, and anelastic connector extending transversely across the first sound box andconnected to the needle arm at one end and to the diaphragm of thesecond sound'box at the other.

2. In a device of the kind described, a sound box having a diaphragm,needle arm brackets at one side of the sound box, a needle arm fulcrumedin said brackets and connected to the diaphragm, a second sound box atthe opposite side of the first sound box and likewise provided with adiaphragm, an elastic connector having connection at one end to thesecond diaphragm and at its other end to the needle arm and otherelastic strands connected respectively to the .needle arm brackets andt0 the first connectr at a point adjacent to said second diaphragm."

an anchorage for the remaining ends of said strands, said anchoragecomprising an amplifier sound box having a diaphragm to which theremaining end of the first strand is connected and a spreader carried bysaid first strand to which the remaining ends of the other strands areconnected.

4. In a device of the kind described, a sound box having a diaphragm,needle arm brackets at one side of the sound box, a needle arm extendingradially across the sound box and having its inner end connected to thediaphragm, said needle arm having a fulcrunr arranged transverselythereof and supported in said brackets,

the fulcrum being disposed between the inner and outer ends of theneedle arm, a bracket extending outwardly from the sound boxdiametrically opposite the needle arm, a second sound box supported onsaid bracket at right angles to the first sound box and provided with adiaphragm, an elastic connector having one end con-. nected to the outerend of the needle arm and the other end connected to the seconddiaphragm, a cross bar carried by said elastic connector adjacent thesecond diaphragm, and elastic strands each connected at one end to anend of the cross bar and on its other end to a respective needle armbracket.

In testimony whereof I allix my signature.

J AMES T. LEITCH.

